Logical Fallacies– the Argument from Ignorance

One of the first things you find out as a skeptic is the fact that all of us humans are vastly ignorant of most of what there is to know, but ignorance isn’t bliss — it’s oblivion. This post deals with a logical fallacy that capitalizes on that ignorance, trying to make it seem like knowledge. Knowledge’s evil twin, the illusion of knowledge. This is the Argument from Ignorance, the Appeal to Ignorance, or the Argumentum ad Ignorantiam for Latin buffs.

This fallacy involves the attempt to make a definite statement on a claim by using what is not known rather than what is, or what is statistically knowable through the Wisdom of Crowds. It often takes the general form of:

No one has proven that Godzilla doesn’t exist, so I conclude that Godzilla is real…

No one has proven that secondhand smoke causes cancer, so it must be harmless…

I’ve never seen any real proof that the Apollo astronauts landed on the Moon, so it must be a hoax…

…etcetera

It’s not fallacious when one has knowledge of a lack of evidence for something for which evidence should logically be, and it’s known what this evidence should be.

It’s not fallacious to act upon incomplete data for precautionary purposes, such as the threat of terrorists, who can be expected to operate in secret until they strike, if and when they do.

Though absence of evidence is not necessarily evidence of absence, nor proof of the non-existence of a phenomenon, it can be evidence for it when put in the right context.

The following is a valid argument:

All of the scheduled openings of this library are listed.

I don’t see a listing of it opening at this hour of the day.

So it must be that the library will be closed until two hours from now.

The logical form of an appeal to ignorance is:

“I don’t have an explanation for X, therefore I have an explanation for X.”

…which is a logical contradiction.

For example…

I see a strange light in the sky.

I can’t think of a mundane explanation for it off the top of my head.

I think it’s an alien spaceship.

Or this…

There are gaps in the fossil record.

I do not know of or understand a naturalistic explanation as to why there are such gaps.

So it must be that a supernatural agency has created or interceded in the creation of life.

A variation of this is Confusing the Unexplained with the Unexplainable, (or the God of the Gaps argument as used by creationists, for where they perceive gaps in our knowledge, ‘Goddidit, ‘Nuff said’…).

This is the mistake in thinking that because one does not know a conventional explanation for something that there is indeed no such explanation and that therefore, a supernatural or paranormal cause for the phenomenon must be inferred.

This is understandable, and is reasoning from psychologically available information rather than an examination of more complex and difficult data that may not come as quickly to mind at the time.

It just so happens that supernatural or paranormal explanations are among the easiest to conceive of on the spur of the moment. They are more immediately available, and we are more prone to them through the biases and heuristics by which our brains operate in their default mode..

In informal argumentation the fallacious use of the appeal to ignorance is not so much a violation of logical form as it is one of procedure, an attempt to thwart the goal of critical reasoning to subvert efforts toward a sound basis for explaining a claim.